Western blot was performed using Anti-ERK5 Polyclonal Antibody (Product # PA5-17689) and a 115 kDa band corresponding to Mitogen-activated protein kinase 7 was observed across cell lines and tissue tested. Upon EGF and sorbitol treatment in HeLa cells, there was a shift in the band size which corresponds to phosphorylated form of ERK5, since it is an autophosphorylated protein. Whole cell extracts (30 µg lysate) of (Fig.a) HeLa (Lane 1), HeLa serum starved for overnight and treated with EGF (100 ng/mL for 15 min) (Lane 2), HeLa treated with Sorbitol (0.5M for 30 min) (Lane 3) were electrophoresed using NuPAGE™ 3-8% Tris-Acetate Protein Gel (Product # EA0378BOX); (Fig.b) PC-3 (Lane 1), DU 145 (Lane 2), NIH:OVCAR-3 (Lane 3), SK-O-V3 (Lane 4), NIH/3T3 (Lane 5), Mouse Testis (Lane 6), Mouse Ovary (Lane 7). Resolved proteins were then transferred onto a Nitrocellulose membrane (Product # IB23001) by iBlot® 2 Dry Blotting System (Product # IB21001). The blot was probed with the primary antibody (1:1000 dilution) and detected by chemiluminescence with Goat anti-Rabbit IgG (Heavy Chain) Superclonal™ Recombinant Secondary Antibody, HRP (Product # A27036,1:6000 dilution) using the iBright FL 1000 (Product # A32752). Chemiluminescent detection was performed using Novex® ECL Chemiluminescent Substrate Reagent Kit (Product # WP20005).